The present invention relates to a printing method and a printer using the same and, more particularly, to a stencil printing method a printer using the same.
A printing method using a digital printer operable with a thermosensitive stencil is extensively used due to its simplicity. The digital printer using a thermosensitive stencil includes a master discharging operation for peeling a used master off a print drum and discarding it into a waste master box. In a master making operation, a stencil paid out from a stencil roll is conveyed by a platen roller while being selectively perforated, or cut, by a thermal head in accordance with an image signal representative of a document image. In a master feeding operation, the perforated stencil or master is wrapped around the print drum. Further, in a printing operation, ink is fed to the master wrapped around the drum in order to print the document image on a sheet. Such operations have customarily been independent of each other and sequentially effected one by one. This, however, increases a first print time (FPT hereinafter), i.e., the interval between the time when the operator presses a master make start switch or a start key and the time when the first printing is produced by the above procedure.
Printers using printing methods improved to reduce the FPT are disclosed in, e.g., Japanese Patent Laid-Open Publication Nos. 61-287781 and 7-257002. The printers taught in these documents each performs the master discharging operation and master making operation in parallel. A new master is temporarily accommodated in master stocking means. After the master discharging operation, the master is drawn out of the master stocking means and has its leading edge clamped by clamping means provided on a print drum. After the master has been fully wrapped around the print drum, a first printing or trial printing is produced. The printer proposed in the above Laid-Open Publication No. 7-257002 is capable of effecting the master feeding operation in parallel with the master making operation. Japanese Patent Publication No. 6-51421 proposes to make a master corresponding to a document while the printing operation using a master corresponding to the previous document is under way in order to increase the printing efficiency.
The printers disclosed in the above Laid-Open Publication Nos. 61-287781 and 7-257002 each is capable of making a master while discharging a used master, and feeding a sheet while making a master. However, such a printer is disadvantageous in that the master feeding operation cannot be effected until the master discharging operation ends, and that the printing operation cannot be effected until the master feeding operation ends. As a result, the print drum must make four full rotations during the interval between the time when the start key is pressed and the time when the print drum returns to its home position after the above sequence of steps. This printer therefore cannot operate rationally in such a way to reduce the FPT, i.e., needs a long FPT. Further, the scheme taught in the above Publication No. 6-51421 cannot perform the discharge of the used master corresponding to the preceding document and the making and feeding of the master corresponding to the following document and printing using it at the same time.